POS0694 WHAT TREATMENT GIVES THE BEST CLINICAL RESPONSE AFTER CESSATION OF JAKi THERAPY IN PATIENTS WITH RA? DATA OF THE TARDIS-RA REGISTRY, A NATIONWIDE BELGIAN BIOLOGIC REGISTRY
Authors: D. De Cock, P. Durez, V. Badot, R. Westhovens, P. Verschueren
Journal: Annals of the Rheumatic Diseases (2022)

Background JAKi represent a new important class in Rheumatoid Arthritis (RA) treatment options. It is unknown which specific bDMARD or mode of action should be selected after stopping a JAKi. Objectives To study if clinical response differs between advanced therapies that are initiated after stopping a JAKi. Methods Patients were included from the electronic platform “Tool for Administrative Reimbursement Drug Information Sharing” (TARDIS). Data from all Belgian RA patients on biologic and targeted therapy are collected here for drug reimbursement. Patients were selected for this analysis if they had stopped JAKi therapy and initiated a subsequent therapy. Patients were grouped by TNFi, T/B cell therapy, IL6i or JAKi therapy. The DAS28 response and proportion of patients in remission at the first follow-up (between 3 and 6 months) were compared between groups. Remission was defined as DAS28&lt;2.6. Analyses were repeated in patients who were prescribed the stopped JAKi as first-line or as subsequent line therapy. Data were compared via χ 2 , Anova and t-tests. Results In total, 1238 patients who had stopped JAKi therapy were included. TNFi, T/B cell therapy, IL6i or JAKi therapy was initiated in 36% (441/1238), 19% (233/1238), 18% (227/1238) and 27% (337/1238) respectively. Most baseline demographic and clinical characteristics differed between groups (Table 1). Table 1. TNFi B/T cell IL6i JAKi p-value Number 441 (36%) 233 (19%) 227 (18%) 337 (27%) Age (years) 55 ± 14 57 ± 13 55 ± 14 59 ± 12 &lt;0.001 Gender (women) 323 (73%) 177 (76%) 186 (82%) 257 (76%) 0.100 Weight (kg) 74 ± 15 79 ± 17 75 ± 15 75 ± 15 0.111 Disease duration (years) 9 ± 8 10 ± 9 11 ± 9 11 ± 9 0.002 HAQ (0-3) 1.6 ± 0.7 1.8 ± 0.6 1.5 ± 0.7 1.5 ± 0.8 0.353 PGA (0-100) 65 ± 20 68 ± 21 67 ± 21 57 ± 24 &lt;0.001 CRP (mg/l) 10 ± 16 14 ± 20 16 ± 28 11 ± 17 0.003 ESR (mm/h) 22 ± 21 24 ± 19 27 ± 21 25 ± 22 0.117 TJC28 8 ± 6 8 ± 6 9 ± 6 7 ± 6 0.001 SJC28 5 ± 4 6 ± 5 6 ± 4 5 ± 5 0.006 DAS28 4.7 ± 1.1 4.8 ± 1.1 4.9 ± 1.2 4.4 ± 1.3 &lt;0.001 2 nd line of therapy after initial JAKi therapy 211 (48% ) 56 (24% ) 52 (23% ) 112 (33% ) &lt;0.001 Numbers given are mean ± SD or number, proportion. TNFi = tumour necrosis factor inhibitor, ts= targeted synthetic, HAQ= health assessment questionnaire, PGA= Patient Global assessment; CRP= C-reactive protein; ESR= erythrocyte sedimentation rate; TJC= tender joint count; SJC= Swollen joint Count; DAS28 = disease activity score based on the 28joints The clinical response could be studied in 577 patients. Patients on rituximab were excluded as these were retreated on flare, following Belgian reimbursement criteria. TNFi, Tcell therapy, IL6i or JAKi therapy was initiated in 37% (211/577), 13% (76/577), 18% (102/577) and 33% (188/577) of these patients respectively. DAS28 decreased on average with 1.7 ± 1.5, 1.6 ± 1.4, 2.4 ± 1.6* and 1.3 ± 1.6 for patients on TNFi, T cell therapy, IL6i or JAKi therapy respectively (*p&lt;0.001). Remission was reached in 42%, 41%, 56%* and 39% for patients on TNFi, T cell therapy, IL6i or JAKi therapy respectively (*p=0.045). Before switching, JAKi therapy was the first advanced therapy in 35% (204/577). In this “naïve” subgroup, DAS28 decreased on average with 1.9 ± 1.5, 1.9 ± 1.3, 2.4 ± 1.8 and 1.0 ± 1.7* for patients on TNFi, Tcell therapy, IL6i or JAKi therapy respectively (*p=0.001). Remission was reached in 44%, 48%, 58% and 35% for patients on TNFi, Tcell therapy, IL6i or JAKi therapy respectively (p=0.279). In the “experienced” subgroup, who started JAKi therapy as subsequent line therapy in 65% (373/577), DAS28 decreased on average with 1.5 ± 1.6, 1.5 ± 1.4, 2.3 ± 1.6* and 1.4 ± 1.6 for patients on TNFi, Tcell therapy, IL6i or JAKi therapy respectively (*p&lt;0.001). Remission was reached in 40%, 38%, 55% and 41% for patients on TNFi, Tcell therapy, IL6i or JAKi therapy respectively (p=0.118). Conclusion Our results show clearly that IL6 inhibitors have a better clinical response after JAKi cessation compared to other mode of actions, including other JAKi. However, considerable baseline differences existed, that could influence our results. Disclosure of Interests None declared